The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
An internal combustion engine compresses and ignites a mixture of air and fuel in one or more cylinders to produce engine power. If the mixture fails to ignite and/or completely burn, an incomplete combustion results in a cylinder misfiring. Misfiring of cylinders can damage engine components, produce unwanted emissions, and/or impact fuel economy.
Cylinders can misfire when the mixture is lean. The mixture may be lean due to various reasons. For example, the mixture may be lean when fuel injectors are partially clogged and/or when the fuel has a high drivability index (HIDI). The HIDI affects fuel combustion as follows.
Fuel is commonly characterized by fuel distillation curves. The fuel distillation curves plot percentages of fuel vaporization as a function of fuel temperature. Normally, X % of fuel may evaporate at a temperature T. Accordingly, Y amount of fuel may yield an air-to-fuel ratio of R at temperature T. However, when the drivability index of the fuel is high, a temperature greater than T is required to evaporate X % of the fuel having the HIDI. Accordingly, when the drivability index of the fuel is high, more than Y amount of fuel is required to obtain the air-to-fuel ratio of R at temperature T.